Application of machine type communication (MTC) refers to data transmission of one or more network elements without human involvement. In the prior art, when a core network device receives a small data packet sent from an machine type communication (MTC) server, the small data packet is transmitted to a User equipment (UE) according to the following steps, where the small data packet refers to a small-sized data packet that sends a relatively small amount of data, and data transmission can be completed generally by using one or more data packets. Because a data amount of small data packets is relatively small and transmission time is also relatively short, there is no need to establish a data channel for these data packets.
S1. The core network device sends a first paging message to a base station that serves the UE, where the first paging message includes the small data packet, and the core network device may be an mobility management entity (MME).
S2. The base station that serves the UE sends a second paging message to the UE, so that the UE sends a radio resource control (RRC) connection establishment request message to the base station that serves the UE according to the second paging message.
S3. After receiving the RRC connection establishment request message, the base station that serves the UE sends an RRC connection establishment message to the UE, where the connection establishment message includes the small data packet.
It can be learned from the foregoing steps that the paging message sent from the core network device to the UE includes the small data packet, so that the base station that serves the UE sends the small data packet to the UE in a process in which the UE performs RRC connection establishment according to a second paging message. However, when the UE does not respond long after the base station that serves the UE sends the second paging message, the base station that serves the UE sends the second paging message again. Consequently, in this process, the small data packet is stored in the base station that serves the UE for a relatively long time. When the base station that serves the UE needs to initiate calls including small data packets to multiple UEs, a quantity of small data packets that are temporarily stored is excessively great, thereby putting a heavier storage burden on the base station that serves the UE, and further affecting data transmission of the base station that serves the UE. In addition, when initiating paging, the core network device sends a first paging message that includes the small data packet to all base stations within a tracking area (TA) location area of a core network with which the UE is registered. Each base station that receives the first paging message pages, within a cell of the base station, the UE. In a process of paging the UE, the base station temporarily stores the small data packet for the UE. Therefore, small data packets that are temporarily stored also put a heavier storage burden on a non-base station that serves the UE.